This invention relates to underwater acoustic minesweeping and countermeasure decoy devices, and more particularly to a towable, self-driven, underwater noisemaking device.
Older existing and previous towed noisemakers, for use as decoys or in acoustic minesweeping, usually have been exceedingly heavy and included complex driving mechanisms not suitable for aircraft deployment and towing. Recent prior art development efforts have been expended for helicopter-towed mine countermeasures. These efforts have produced lighter-weight devices, but they still suffer from the mechanical complexity of the drive mechanism. Also some prior art devices extract the driving energy from the water flow by an axial impeller, which through gearing, drives a planar disc for noisemaking about a vertical axis. The mechanical transfer through gears, to this usual vertical-axis shaft, results in adverse rolling and yawing moments on these towed devices. These disadvantages result directly in severe operational problems in regard to gear trimming and aircraft operational safety.